In a computing environment, searching for particular documents and/or documents that are relevant to a particular category can involve posing a query to a search engine. Often a user may be looking for documents pertaining to a particular topic, or even for a specific document, and will create a query that helps identify the document or documents. Commonly, searches involve a set of documents, such as an Internet user searching for web-pages on a particular topic, or an employee of an enterprise searching for a document from the enterprises data storage system. In these examples, the set of documents searched by the user (web-pages on the Internet and files in a server system) are often indexed to facilitate query-based searching. An index can comprise data that represents the documents in a manner that allows query-based searching. Further, the structure of an index allows the information to be updated, such as by a web-crawler adding pages to the search index.